Engine/Transmission (1994 - 1998) Vacuum pump

[SAndreasen]

What is the spec for the vacuum pump ? And where Is a good place to hook a vacuum gauge to check the pump ?

 

[BigPapa]

I don't see any specs listed. If it sucks, it sucks.......

I would test at the fitting on the pump.

 

[SAndreasen]

I don't see any specs listed. If it sucks, it sucks.......

I would test at the fitting on the pump.

Thanks I though I seen a spec somewhere the other day but I couldn't remember I think mine might be getting a little weak

 

[BarryG]

I think it is mid to upper 20's. Pretty sure the spec on my 01 was 28 but may have been a little less perhaps 26 I would test it at the "T" on the firewall from where the vacuum pump line comes up there and splits off to various things (at least that is where it was on my 01.

 

[Bob4x4]

in the 95 fsm diag for the low vacuum switch says 8.5 to 25 is the range.In the real world I normally saw 20+

 

[SAndreasen]

in the 95 fsm diag for the low vacuum switch says 8.5 to 25 is the range.In the real world I normally saw 20+

What does the low vacuum switch do

 

[SAndreasen]

#@$%!The reason for all this sometimes my air vent switch selector won't change the air output to the different settings . Not that there's any heat coming out of the vents anyway#@$%!#@$%!#@$%!

 

[surfbeetle]

Check the hose coming from the vacuum pump, mine collapsed and had to be replaced. Also at some point, I also had to rebuild it with a kit from http://www.fixinrams.com/

 

[mwilson]

I had an actuator go bad on the '97. The one right by the throttle cable.

Pump up the vacuum with a Mighty Vac, have enough hose to allow you to be in the cab. Then walk the heater controls through each setting while watching the gauge...that's how I found the ruptured diaphragm in the actuator...

 

[mwilson]

The above assumes that all other leaks to the vacuum have been repaired or the system is tight.

 

[Bob4x4]

I had an actuator go bad on the '97. The one right by the throttle cable.

Pump up the vacuum with a Mighty Vac, have enough hose to allow you to be in the cab. Then walk the heater controls through each setting while watching the gauge...that's how I found the ruptured diaphragm in the actuator...

Back in the day chrysler had issues with doors dropping out on grades.It was extreme on the v6 powered van conversions,so I built a test rig using an ac vacuum pump and created a fixed vacuum leak making it easy to find small leaks with more speed and acuracy

 

[SAndreasen]

What's a good way to find a vacuum leak

 

[mwilson]

Mighty Vac Hand Held Vacuum Pump. Unplug the line from the trucks vacuum pump and start there. Work your way back and isolate lines at the firewall tee.

 

[Bob4x4]

What does the low vacuum switch do

it warns of a low vacuum condition that will leave you without brake assist

 

[GAmes]

it warns of a low vacuum condition that will leave you without brake assist

It activates the ABS light when vacuum is low. It is also causes the ABS light to illuminate when it fails.

 

[Bob4x4]

It activates the ABS light when vacuum is low. It is also causes the ABS light to illuminate when it fails.

That is correct